interface Shape {
  color: string
}
interface PenStroke {
  penWidth: number
}

interface Square extends Shape, PenStroke {
  sideLength: number
}

let squre = {} as Square
squre.color = 'blue'
squre.sideLength = 10
squre.penWidth = 5.0

console.log(squre)
// { color: 'blue', sideLength: 10, penWidth: 5 }

export {}